Tonight I learned about some interesting features with PDF files in C3D 2010. As we all know creating PDF files of our drawings,exhibits and plans sheets has become one of the best and fastest way to exchange data information between client, developers, architects, and engineers. C3D 2010 comes with a new PDF print driver, which comes with the new release of the underlying AutoCAD software. One of the most unique feature is the inclusion of layers in the PDF output for control of visibility. What this means that some of the C3D objects are carried over into the PDF file as layers which allows the user to turn off and on in the PDF reader. I have provide a short video demonstration below of how it work. Enjoy.